at one point this was based on std::auto_ptr and didn't
free its arg on failure

Adapt description to reality

Change-Id: I24133fb6c52bd7500037364120cb11d1b1f099c2
(cherry picked from commit f161cdc9)

Change-Id: I8aeed6876d80b7ebe4ebb5e2cfd12e00420bd207
Reviewed-on: https://gerrit.libreoffice.org/51933Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Jenkins <ci@libreoffice.org>
(cherry picked from commit 28632f5c)